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Qubit Reader Brings Quantum Computing Closer

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The development of a compact sensor that can access information stored in the electrons of individual atoms brings scalable quantum computing in a silicon chip one step closer. The development, conducted within Prof Michelle Simmons’ group at the Centre of Excellence for Quantum Computation and Communication Technology at The University of NSW, was published in Physical Review X (

Quantum bits (or qubits) made from electrons hosted on single atoms in semiconductors are a promising platform for large-scale quantum computers due to their stability. Creating qubits by precisely positioning and encapsulating individual phosphorus atoms within a silicon chip is a unique Australian approach that Simmons’ team has been pursuing.

However, the number of connections and gates required to scale up the phosphorus atom architecture has been a challenge. “To monitor even one qubit, you have to build multiple connections and gates around individual atoms, where there is not a lot of room,” Simmons says. “What’s more, you need high-quality qubits in close proximity so they can talk to each other – which is only achievable if you’ve got as little gate infrastructure around them as possible.”

Compared with other approaches for making a quantum computer, Simmons’ system already had a...

The full text of this article can be purchased from Informit.